Hatchbacks, passenger vans, and some sport utility vehicles are equipped with a rear compartment that is accessed via a hatch panel or liftgate which swings open on a hinge. The hatch may be a glass panel. In order to securely park the vehicle, the hatch or liftgate is typically closed and locked using a conventional keyed latch claw and anvil mechanism that engages a U-shaped “striker bolt, also sometimes termed a “staple,” mounted on the hatch panel. Lock mechanisms of this type are described by Sarosy in U.S. Pat. No. 4,157,844, as shown in FIG. 1, for example.
However, the rear compartment can overheat if not ventilated. Children, pets or groceries in the vehicle may require ventilation and a useful solution is a latch extension that allows the hatch or liftgate to be secured with a fixed gap for cross-ventilation. The driver may then lock the vehicle with the hatch or liftgate in a partially open but secure position.
For latching a trunk of a car in a partially open position, Gardels in U.S. Pat. No. 2,618,497 described a spacer bar with two modified ends. A variety of very complex single-piece configurations are illustrated that are not easily or inexpensively manufactured. Moreover, none of the options disclosed by Gardels are adapted to modern hatchback closures, which include a “striker bolt” or “staple”, typically a U-shaped bolt, and a “latch claw” with spring-operated, reciprocating cam finger for operatively receiving and engaging the striker bolt. The latch claw is generally mechanically coupled to a keyed cylinder for unlocking and releasing the hatch or liftgate, but may include a power lock option.
Rushbaum, in U.S. Pat. No. 4,278,280, describes an adjustable strut for securing the lid of a trunk of a vehicle in a partially open position. However, the device must be clamped at an angle into a particular design of latch in order to lock securely and is not useable with most hatchbacks. Similarly, U.S. Pat. No. 4,667,993 to Hannesson describes a spring-loaded strut that is hooked in place to secure a trunk when carrying a load.
Disadvantageously, the adjustable length of these struts allow an intruder sufficient clearance to gain access to the vehicle.
Also of interest is the latch extender described by Frayne in U.S. Pat. No. 5,165,742, which is adapted for screwing onto a staple of a pivoting window latch assembly and then lockedly inserting via an extension bit into the latching mechanism. However, the bolt, shown as a wing nut, for engaging the device on the staple can be unbolted by an intruder seeking to gain entry to the vehicle and the device has several parts, which can become lost between uses.
Thorlton, in U.S. Pat. No. 5,551,738 describes a one-piece latch extension rod (20) shown in FIG. 2, which consists of a bent rod with two legs and two tang elements (26a,26b) for twistingly engaging a hasp (21) of a hatch window (24) so as to secure the hatch window to an external frame (23) of the vehicle. Opposite the tangs, the bent rod is formed as a striker bar (27), which is inserted into a conventional lock (22) with latching claw and lock anvil. Once pinched in the claw of the latch, the tangs cannot be untwisted to disengage from the staple (21). The tang elements secure the hatch against upward motion but not against downward motion in the staple, so the hatch window for example can be slammed against the tangs, possibly breaking the hatch window panel. The legs are installed with a spring force pinning the tangs (26a,26b) inside the staple (21) in an effort to reduce vertical sliding while in use. The need for spacer rod (25) underlines the problem of unwanted motion. Moreover, one leg (28) is longer in length than the other and is labeled with an identifying band (29) because the device must be inserted into the lock in a particular orientation, a feature that can be easily confusing.
U.S. Pat. No. 6,048,005 to Rotondi describes a hoop-shaped extension striker that is pivotably bolted to the existing vehicle striker of a rear window. Once installed, the device can be unbolted by reaching into the gap under the window and unscrewing the bolts and is not truly secure.
Taken as a whole, the above devices have an assortment of problematic issues which can deter the potential user. Thus there remains a need in the art for a latch extension device that overcomes the above disadvantages, inserts without tools into a conventional lock mechanism, and engages the vehicle's striker bar to form a tight fitting and rigid extension structure that reversibly and lockably secures a hatch or door in a partially open position, thereby providing a fixed gap for ventilation and cooling without jeopardizing personal security.